NASA today received formal approval from the White House
Office of Science and Technology Policy (OSTP) to proceed toward
the launch of the robotic Cassini mission to explore Saturn and
its moon Titan.

"NASA and its interagency partners have done an extremely
thorough job of evaluating and documenting the safety of the
Cassini mission. I have carefully reviewed these assessments and
have concluded that the important benefits of this scientific
mission outweigh the potential risks," said OSTP Director Dr.
John H. Gibbons, who signed the launch approval.

NASA Administrator Daniel S. Goldin said, "I am confident in
the safety of the Cassini mission, and I fully expect that it
will return spectacular images and scientific data about Saturn,
in the same safe and successful manner as the Voyager, Galileo
and Ulysses missions."

White House launch approval is required by presidential
directive due to the type of power source used to provide
electrical power for the Cassini spacecraft and its scientific
instruments, and the heater units that it carries to keep the
spacecraft's instruments and electronics warm in deep space.

The radioisotope thermoelectric generators (RTGs) and
radioisotope heater units used to power Cassini and keep its
internal systems warm have been used in previous NASA missions
ranging from Apollo to Galileo, and have been approved by five
previous administrations ranging from Nixon to Bush. RTGs produce
power by the heat generated through the natural radioactive decay
of non-weapons-grade plutonium dioxide, which is transformed into
electricity by solid-state thermoelectric converters.

Before Administrator Goldin sent the request for launch
approval to OSTP, two separate processes were completed to
address the environmental and safety aspects of the mission. NASA
completed an environmental impact statement in June 1995 and a
supplement in June 1997, as required by the National
Environmental Policy Act and NASA policy.

Consistent with long-standing Presidential policy, the
Department of Energy (DOE) prepared over the past seven years a
comprehensive safety analysis report. In addition, an Interagency
Nuclear Safety Review Panel, including safety experts from DOE,
NASA, the Department of Defense (DOD), the Environmental
Protection Agency (EPA) and a technical advisor from the Nuclear
Regulatory Commission, conducted a comprehensive evaluation of
the safety analysis. This panel was supported by more than 50
scientific experts from academia and industry.

DOD, EPA and DOE have written to the NASA administrator
confirming that, in their view, the safety analysis conducted for
the mission is comprehensive and thorough.

Cassini is a cooperative endeavor of NASA, the European
Space Agency (ESA) and the Italian Space Agency, or Agenzia
Spaziale Italiana. The mission will send a sophisticated robotic
spacecraft, equipped with 12 scientific experiments, to orbit
Saturn for a four-year period and study the Saturnian system in
detail. The ESA-built Huygens probe that will parachute into
Titan's thick atmosphere carries another six scientific
instrument packages.

Saturn is the second-largest planet in the solar system and
is made up mostly of hydrogen and helium. Its placid-looking,
butterscotch-colored face masks a windswept atmosphere where jet
streams blow at 1,770 kilometers per hour (1,100 miles per hour)
and swirling storms roil just beneath the cloud tops. Previous
spacecraft passing by Saturn found a huge and complex magnetic
environment, called a magnetosphere, where trapped protons and
electrons interact with each other, the planet, rings and
surfaces of many of the moons.

Although it is believed to be too cold to support life,
haze-covered Titan is thought to hold clues to how a primitive
Earth evolved into a life-bearing planet. It has an Earth-like,
nitrogen-based atmosphere and a surface that many scientists
believe probably features chilled lakes of ethane and methane.
Scientists believe that Titan's surface is probably coated with
the residue of a sticky brown organic rain.

The launch of Cassini aboard a Titan IV-B/Centaur launch
vehicle is scheduled for 4:55 a.m. EDT on October 13 from Cape
Canaveral Air Station, FL. An on-time launch will deliver the
Cassini mission to Saturn almost seven years later on July 1,
2004. Cassini's primary mission concludes in July 2008.